Ask Dr. Halverson: New study: Risk of catching coronavirus on airplanes very low

web 4 17 Halverson photo

By Dr. Jim Halverson

Travelers concerned about contracting the coronavirus on a flight can breathe at least a small sigh of relief following new evidence that there is a very low risk of catching COVID-19 onboard an airplane.
In a study released on Oct. 8, the International Air Transport Association (IATA) found only 44 confirmed cases of COVID-19 caught on a flight from among the 1.2 billion people who flew between January and July. That translates to one case for every 27 million flyers.
IATA, as well as experts from Airbus, Boeing and Embraer, all agree that the combination of wearing a mask and the constant airflow through high-efficiency particulate air (HEPA) filters keeps airline cabins very safe. 
Airflow in airliners
Air enters the airliner’s cabin from overhead inlets and flows downward toward floor-level outlets. Air enters and leaves the cabin at the same seat or in very nearby rows only. There is little airflow forward and backward between rows, making it less likely to spread respiratory particles between rows. The airflow in current jet airliners is also much faster than normal indoor buildings. Half of it is fresh air from outside. The other half is recycled through HEPA filters of the same type used in operating rooms. Any remaining risk to be managed is from contact with other passengers who might be infectious. Seat backs provide a partial physical barrier and most people remain relatively still while flying, with little face-to- face contact with other passengers and crew.
HEPA filters
HEPA (high-efficiency particulate air) filters are a very high-intensity system of fibers that air is run through to filter out a large amount of contaminants, including dust, moisture and biological elements. According to the Centers for Disease Control and Prevention, HEPA filters capture 99.9% of particles (bacteria, fungi and viruses) as small as 0.1 to 0.3 micrometers in diameter. The coronavirus averages 0.125 micrometers in diameter. Cabin air passes through these filters 20 to 30 times per hour. 


Be safe if you must travel
Though the actual air flight is quite safe, it is imperative if you must fly that you also follow all safeguards for the duration of your trip. This starts with trip planning. Will you require public transportation to get to the airport? If so, wear a mask for that drive until you are safely at your final destination. Is the airline you are flying screening all passengers and trying to keep passengers distant in waiting areas? How close will people be seated in the rows near you?
 Take hand sanitizer and use it frequently. Make sure to maintain social distancing in the airport and avoid restaurants. Leave your mask on for the entire flight unless having a snack. When you arrive, continue the same precautions until you have reached your hotel room or home you are staying at.
Make sure to consider the area that you are going to and who you will be seeing. The CDC maintains very up-to-date information about the current status of COVID 19 worldwide. If you are visiting someone, are you increasing their risk, or are they increasing yours, by spending time with them? Also, please remember that a negative test only means that you do not have detectable levels of the virus at the time of the test. If you have had a high-risk exposure for up to 14 days before your flight, do not travel!
Many states are currently also not mandating the same safety guidelines that California is requiring. I would highly advise you to not travel to more permissive states unless their incidence of COVID-19 is extremely low. 
The airline’s safeguards and safety record are another great example of how we are learning to live with the coronavirus. However, travel still should be only for essential reasons. Our Ojai Valley continues to be quite safe. Please do not increase your risk and the risk to your family here at home, friends in our community and neighbors by not maintaining your excellent safety practices when you are out of our area.
Stay committed, stay properly informed, stay safe and stay well.


— Dr. Jim Halverson is a longtime Ojai physician who writes a weekly column on COVID-19 for the Ojai Valley News.


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